Abstract
In the conventional spot welding process, the heat generation in welds makes use of resistance heating of workpieces and the workpieses are jointed by nugget formed at the interface of them. However, in this process, the indentation of workpiese increases with the size of nugget.
The problem described above is improved by means of using the pulsed high current density with very short duration, because the contact resistance at the interface is used efficiently to form nugget and the thermal loss is obstructed.
In this welding process, tensile shear strength and peel strength of welding joint are sufficiently large, and fusion layer is very thinner than one of the conventional spot welding, and its indentation is very small.
It seems that the joining of workpieses is occured mainly due to Joule's heating at the interface by contact resistance.
